Osman

Osman (1258-1324), Turkish leader, considered the founder of the Ottoman dynasty. The son of Ertogrul (died about 1280), a chieftain in the service of the Seljuk sultan of Rūm, Osman made himself ruler of a small state in northwestern Anatolia, capturing the towns of Eskişehir, Bilecik, Yarhisar, and Yenişehir from the Byzantines. From this base, his descendants extended their rule throughout Asia Minor and the Balkans and eventually over the whole eastern Mediterranean. Othman and Ottoman are variant spellings of Osman.